When an airplane is taking off, there is no operational flight director on the vertical axis, that can be used to assist a pilot during said take-off. The expression “take-off of the airplane” should be understood here to mean the travel to the take-off, the rotation phase and until power cut-back plus a few seconds (typically 5 seconds). In particular, during the rotation phase, the pilot has to perform the rotation without the assistance of a flight director, to achieve a certain trim (typically 15°) with a certain pitch rate (typically 3°/s).